Pumping-engine



(No Model.) W. A PERRY- PUMPING ENGINE. No. 251,730. Patented Jan. 3,1882.

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; UNITED STATES PATENT OFFICE.

WILLIAM A. PERRY, OF BAY RIDGE, NEW YORK.

PUMPING-ENGINE.

SPECIFICATION forming part of Letters Patent No. 251,730, dated January 3, 1862.

' Application filed June 27, 1881. (No model.) 7

To all whom it may concern Be it known that I, \NILLIAM A. PERRY, a citizen of the United States, residing in the city of Bay Ridge, county of Kings, and State of New York, have invented certain new and useful Improvements in Pumping Engines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to an improved mode of using steam 'expansively in direct-acting pumping-engines of the form known as the Worthington Duplex Pu m ping-Engine, patented as No. 24,838 on July 19, 1859, and as No. 116,131 on June 20,1871. In these engines the amount of expansion is limited by the necessity of maintaining a nearly uniform propulsive power during the whole length of the stroke, and also of dividing the power produced by the steam in such manner that each side of the duplex engine shall develop onehalt of the total power. This enables two plungers of equal diameter to be used, as is requisite to secure a uniform discharge of water fiom the pump cylinders into the receivingmain. Inasmuch as direct-acting engines of this class can use steam to the best advantage by compound cylinders, the arrangement and proportion of such compound cylinders becomesamatterot'greatimportance. Thiscoinpounding has hitherto been done in one of two ways, either by having one high pressure or direct steam-cylinder and one expanding or low-pressure cylinder upon each side, making four in all, or as. in the tank-engine patented to H. 1%. Worthington as No. 116,131 on June 20,1871, wherein the high-pressure cylinder formed one side of the engine and the expanding-cylinder the other, each operating a separate pump-plunger. It is evident that with either of these arrangements the ratio of the high-pressure to the expanding cylinder must be limited to that which, with a given steampressure, would secure an equal development of power from each side of the engine.

The object of this invention is to avoid the limit imposed upon the amount of expansion by the piinciples of construction just described and enable a higher rate of expansion to be used, and also to furnish a mode of construc tion which shall admit of more adjustments to better-compensate for the variations in the initial or boiler pressure.

My invention consists in the addition of an expanding-cylinder to the high-pressure cylinder upon one side of the engine only, the other side of the engine consisting of a still larger expanding-cylinder,into which the steam is conducted after operating in both the high and the, low pressure cylinders upon the opposite side of the engine. It is obvious thatwith this arrangement the steam is used much more economically and efficiently upon the high-pressure side of the engine, and that the high-pressure cylinder can and must be relatively much smaller in proportion to the opposite cylinder than if the intermediate cylinder were not used.

With the arrangement of cylinders proposed above a tank may be used, as described in PatentNo. 116,131, of 1871; or the exhaustfrom the first' expanding-cylinder may be carried directly to the second upon the opposite side of the engine.

In the drawings annexed, Figure 1 is a side elevation of a duplex pumping-engine fitted with my improvements; and Fig. 2 is a plan of the same, a tank being shown connected with the two expanding cylinders, and the pumping apparatus being merely indicated by the ends ot'the water-cylinders at 1.

2 is the high-pressure cylinder; 3, the expanding-cylinder associated with it upon one side of the engine, and 4 the expanding-cylinder constituting the other side of the engine. 5, 6, and 7 are the steam chests of the cylinders 2, 3, and 4; 8, 9, and 10, the inlets to the respective steam -chests, and 11, 12, and 13 their respective outlets or exhaust-pipes. 14 is the tank; 15, a pipe connecting with it, and 16 a valve or cock in said pipe. The inlet 8 takes live steam from the boiler for the highpressure cylinder 2, the pipes 11 and 9 lead the steam cylinders 2 to 3, the pipes 12 and 10 from 3 to 4, and the pipe 13 connects with the condenser if one he used. The pipe 15 connects the tank with the pipe from 12 to 10, and there fore places both the expandingcylinders in connection with the tank, the rate at which the steam enters and leaves the tank being regulated by the cook 16, which may also be employed to shut ofl' the tank from both cylinders when desired.

By such a construction it is evident that the ultimate rate of expansion may be varied by arranging the point of cut-01f in either the high-pressure cylinder or the expandingcylinder upon. the same side, and that I can thus modify the power developed in each of such cylindersandits relation to thepowerobtained and that developed in the third cylinder upon the other side. The mechanism described therefore permits the expansion of the steam to a much greater degree, and is therefore less afiected by variations in the boiler-pressure than a two or four cylinder compound engine, in which the steam passes only through two cylinders.

In the drawings, the first expanding-cylinder is shown arranged in the same axial line as the high-pressure cylinder; but it may be made to surround the former and be provided with an annular piston,.or arranged in any other desirable position.

Iam aware that in a duplex pumping engine provided with an expanding cylinder upon each side, the derangement of speed caused by variations in the initial pressure is much less than in the two-cylinder expanding engine, because both sides of the engine are aifected nearly alike by such variations; but the complication of the parts and the great cost of such a mode. of construction render the two-cylinder or tank engine cheaperin construction, and therefore more acceptable in many cases.

Byvthe invention described herein the obi jections to the two-cylinder expanding engine are removed, the desired increase in rate of expansion secured, and a means of regulating or controlling the movements of the respective pistons is provided at a much lower expense than the employment of the two-cylinder expanding engine.

What is claimed is 1. The improvement in compounded duplex steam pumping-engines, consisting in the combination of a high-pressureand an expanding cylinder, co-operating upon one side of the engine, with an expanding cylinder operating alone upon the opposite side, the Whole being arranged and operated to produce an equal development of power upon both sides of the engine, substantially as and for the purpose set forth.

2. The combination, with the high-pressure and expanding cylinders arranged and operated, as herein described, upon one side of a duplex pumping-engine, ot' the intermediate tank and single expanding-cylinder operating alone upon the opposite side of the engine, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in the presence of two subscribing wit Witnesses:

T. H. PALMER, GEO. H. GRAHAM. 

